The administration may decide this week on a 19-month troop withdrawal plan, military officials say. Obama has advocated a 16-month timetable and military officers pushed for a 23-month plan.

WASHINGTON — The Obama administration is close to deciding on a 19-month withdrawal plan for the bulk of U.S. troops in Iraq and could announce a timetable this week, military officials said Tuesday.

The plan would represent a compromise between the 16-month withdrawal timetable President Obama advocated during his campaign and the military's proposal for a 23-month time frame.

Under the proposal being considered, all combat forces would be pulled out of Iraq by late 2010, but a "residual force" of as many as 50,000 soldiers would remain.

A stepped-up Iraq withdrawal timeline is crucial to the administration's plans for increasing the number of troops in Afghanistan. It is also crucial to its plan to cut the federal deficit by reducing the cost of overseas deployments.

Although officials expect an announcement this week, a White House official said Tuesday that Obama had not yet made a decision on the precise timetable.

Obama offered no details of his plans in his speech to Congress on Tuesday night, though he renewed his promise to outline his Iraq exit strategy quickly.

"I will soon announce a way forward in Iraq that leaves Iraq to its people and responsibly ends this war," he said.

The Defense Department this month presented a 19-month withdrawal plan, along with the 16-month and 23-month options, to the administration, military officials said.

A security agreement between U.S. and Iraqi officials requires that all U.S. forces leave by the end of 2011, although that deal could be renegotiated to allow a longer American presence if the Iraqis request such help.

Army Gen. Ray Odierno, the top U.S. commander in Iraq, and other officers had pushed for the 23-month timeline to keep a large number of troops in place for national elections scheduled this fall. A 19-month timeline would require the military to begin withdrawing some units before the elections.

But with the security gains of recent months, officers believe the 19-month compromise plan will work.

"Based on what we think is going on, that would be a reasonable timeline," said a senior military officer who spoke on condition of anonymity because a final decision had not been made.

"The thing I would pay attention to is what will remain," the officer said. "The key decision for the president is: What is that force, and what specific duties does it have?"

Military officials said the remaining troops would train the Iraqi army, conduct counter-terrorism missions, provide logistics help and offer aerial surveillance and airstrikes. The senior officer said the troops also could help protect Iraq from outside attack, something the Iraqis cannot yet do.

"When President Obama said we were going to get out within 16 months, some people heard, 'get out,' and everyone's gone. But that is not going to happen," the officer said.